Reversing Hydraulic Fan Drives Stephen Frantz Staff Engineer - - PowerPoint PPT Presentation

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Reversing Hydraulic Fan Drives

Stephen Frantz

Staff Engineer Danfoss Power Solutions

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Benefits/Requirements for a Reversing Hydraulic Fan Drive

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For 15-45 kW Systems 25 kW Focus

Benefits

Increased fan efficiency Increased machine uptime

Requirements

Returns to forward in the event

• f a control signal loss

Minimal impact on power availability for work functions Minimal usage of space on machine Minimal impact on machine reliability/downtime

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Review major system design considerations Review two current typical reversing hydraulic fan drives Two “new” options to consider

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• System Design Considerations

– Power loss due to the reversing function – Machine space required for the reversing function – Installed (component and installation) cost – Operating costs – System reliability

• Number of components and potential failure points (including

leaks) along with the ability to diagnose and service

– System flexibility

• Number of and size of components, maximum operating

pressures, potential to use pump flow for other functions, reversing controllability

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Parameter for Consideration Open Circuit Type 1 Open Circuit Type 2 Closed Circuit Open Circuit Type 3 kW Loss - reversing Peak Average Volume (cm^3) Full system Reversing function Installed Cost Operating Costs System Reliability System Flexibility

Table Data Based on 25kW Fan Power System

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Open Circuit System 1

Fixed displacement pump(s) Fixed displacement motor Speed control valve (variable pressure relief valve) Reversing valve (directional control valve)

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Open Circuit System 2

Variable displacement pump Fixed displacement motor Reversing valve (directional control spool valve)

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One Common Thread – Directional Control Valve

Increases cooling system load on the engine, along with

• perating costs

Increases required capacity for cooling system along with installed cost and space Adds to system complexity, can reduce reliability and ability to service.

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Parameter for Consideration Open Circuit Type 1 Open Circuit Type 2 Closed Circuit Open Circuit Type 3 kW Loss - reversing Peak Average 2.8 1.1 2.0 0.8 Volume (cm^3) Full system Reversing function 5000-15000 1000-3000 9000-16000 1000-3000 Installed Cost 1 – 1.2 1.1 – 1.4 Operating Costs System Reliability System Flexibility

Table Data Based on 25kW Fan Power System

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• Closed Circuit System

– Variable Displacement Pump with Fan System Control – Fixed Displacement Motor

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Open Circuit System 3

Variable displacement pump Reverse displacement motor

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Parameter for Consideration Open Circuit Type 1 Open Circuit Type 2 Closed Circuit Open Circuit Type 3 kW Loss - reversing Peak Average 2.8 1.1 2.0 0.8 Volume (cm^3) Full system Reversing function 5000-15000 1000-3000 9000-16000 1000-3000 11300-16200 7500-11900 1500 Installed Cost 1 – 1.2 1.1 – 1.4 1.3 – 1.4 1.1 – 1.2 Operating Costs System Reliability System Flexibility

Table Data Based on 25kW Fan Power System

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Benefits/Requirements for a Reversing Hydraulic Fan Drive

~

For 15-45 kW Systems 25 kW Focus

Benefits

Increased fan efficiency Increased machine uptime

Requirements

Returns to forward in the event

• f a control signal loss

Minimal impact on power availability for work functions Minimal usage of space on machine Minimal impact on machine reliability/downtime

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• How to View my Technical Paper NOW!

1. Download the Danfoss Power Solutions app 2. Log in or Create an Account 3. Click on “IFPE 2014” 4. Click “Unlock Passcode” 5. Enter Code

CODE:

9178

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Questions

How to View my Technical Paper NOW! 1. Download the Danfoss Power Solutions app 2. Log in or Create an Account 3. Click on “IFPE 2014” 4. Click “Unlock Passcode” 5. Enter Code

CODE:

9178